Traffic lights are ubiquitous from city streets to country roads. Traffic lights traditionally in the United States consist of three lights: green signifying traffic may pass, yellow signifying that traffic will soon come to a stop, and red signifying traffic must stop. These lights are generally vertically aligned, one on top of the other. In this way, traffic lights control traffic at an intersection. In other locations different conventions may be adopted, such as flashing yellow meaning traffic may pass.
Some conventional traffic lights are illuminated using incandescent light bulbs. Incandescent bulbs tend to use relatively large amounts of electricity and require periodic replacement as the bulbs burn out. These factors make the operation of incandescent traffic lights relatively expensive.
More recently, traffic lights are being illuminated using light emitting diodes (LEDs). LEDs provide a source of light that has relatively low energy consumption, and the do not bum out as easily as light bulbs.
While conventional LED traffic lights are less expensive to operate, however, they maintain the conventional approach of three lights, vertically aligned, one on top of the other. While this approach has been used for a very long time, the use of a yellow light to signify that traffic will soon come to a stop has inherent problems. Specifically, motorists approaching a yellow traffic light do not know how much longer the traffic light will continue to stay yellow. These motorists may then unnecessarily speed up creating a safety risk for other motorists and pedestrians or come to a stop unnecessarily abruptly, thereby, creating a safety risk for other motorists.
Additionally, there is a need for quick dissemination of important information to motorists and pedestrians alike. This information may concern traffic conditions ahead or it may concern instructions disseminated in the event of an emergency. Because of the ubiquity of traffic lights, they are well suited for the conveyance of important information. Conventional traffic lights, however, fail to live up to fulfilling this objective.
Furthermore, the ubiquity of traffic lights make them well suited for the conveyance of advertisements that can be tailored to the particular community in which the traffic light is located. The use of advertisements on traffic lights can deliver an aesthetically pleasing futuristic look and be an important source of additional revenue for town and city governments that are increasingly under financial pressure. Conventional traffic lights fail to live up to fulfilling these objectives as well.